The present invention relates to networks, and more particularly to management of network circuits.
A network includes nodes (also called network elements, or NEs) interconnected by links. A network circuit can traverse one or more NEs. Each intermediate NE performs a cross connect function connecting the circuit data from one link to another to deliver the data to the circuit destination.
Computerized network management systems (NMS) have made it easier for human users to create, delete, and modify circuits. An NMS can run on a computer connected to an NE. To create, delete, or modify a circuit, a user issues a command to the NMS. The NMS in turn issues commands to each NE through which the circuit passes. The NEs configure themselves as needed.
The NMS can also use the user""s commands as a source of information on circuits in the network, and can display that information back to the user.
It is desirable to provide improved NMS systems.
The inventors have observed that if a command issued by an NMS is not executed by an NE due to some failure, the NMS will not have correct information on circuits in the network. Further, a circuit may be created, deleted, or modified by another NMS. Neither NMS will be informed of changes performed by the other NMS. This complicates network management.
In some embodiments of the present invention, an NMS receives, from the NEs, information on the cross connects actually set up by the NEs. Therefore, the NMS has correct, up-to-date information on the cross connects. The network management is therefore facilitated.
In some embodiments of the present invention, an NE stores circuit information other than cross connects. Examples of such information include the source and destination NEs for the circuit. The NMS receives that information from the NEs.
In some embodiments, the NMS does not have to have any cross connect or circuit information when the NMS starts up. The NMS gets such information from the NEs.
In some embodiments, multiple NMS systems are used to manage the network concurrently. If one NMS creates, deletes or modifies a circuit, the other NMS systems are informed by the NEs.
Some embodiments allow prompt elimination of orphaned cross connects. An orphaned cross connect may result from an NE being unable to remove a cross connect when a circuit is being deleted. For example, the NE may have temporarily lost power, or a network link may have been temporarily disconnected, when the NMS issued a command to delete the cross connect. When the NE returns on line, the NMS queries the NE and discovers the orphaned cross connect. The user will be informed, and will have an opportunity to issue a command to delete the orphaned cross connect.
Other features and advantages of the invention are described below. The invention is defined by the appended claims.